Gelation induced reversible syneresis via structural evolution

Abstract

This paper reports a large volume change in a cholesterol based molecular gel in the presence of multi-amine as the gelling solvents dissociated from the gel in a dynamic manner. The release capability can be controlled by the ratio of multi-amine. The shrinkage capability can be restored and recycled by a gel–sol transformation. The mechanism of the shrinkage was followed by SEM, confocal laser scanning microscopy and X-ray diffraction studies. A structural evolution from lamellar vesicles to a more compact hexagonal structure driven by competitive intermolecular hydrogen bonds was proved to dominate the process of the solvent release. Moreover, the process can be stopped by addition of organic acid such as trifluoroacetic acid, which favors the application of this kind of material for molecular delivery systems.